This article was co-authored by Jennifer Boidy, RN. Jennifer Boidy is a Registered Nurse in Maryland. She received her Associate of Science in Nursing from Carroll Community College in 2012.

There are 15 references cited in this article, which can be found at the bottom of the page.

Digestion is the process by which humans break down food into component molecules. Digestion is necessary because the smaller molecules can be absorbed and utilized by the body to build structures and promote vital functions. Food supplies humans with macromolecules like proteins, lipids, and carbohydrates, as well as vitamins and minerals. If this overview catches your interest, you may want to take a course in anatomy and physiology to learn more.

Steps

Method1

Breaking Down the Structures of Digestive System

1

Start at the mouth. The digestive system starts at the mouth. You take in food and drink from your mouth and pass it down to the rest of your digestive track. The mouth also starts mechanical and chemical digestion of the food.[1]

2

Follow the path of food to the stomach. The esophagus is the long tube that connects the mouth to the stomach. When you swallow food, it travels down the esophagus until it reaches the stomach. In the stomach, the food is combined with hydrochloric acid and enzymes that break the molecules down.[2]

3

Recognize that the endocrine system aids in digestion. The endocrine system consists of glands that produce hormones. One of these glands, the pancreas, also aids in digestion. The pancreas produces enzymes that help the body break down proteins and regulate blood sugar.[3].

4

Know where most nutrients are absorbed. The majority of nutrients are absorbed in the small intestine. This organ is broken into three sections: the duodenum, the jejunum, and the ileum. Each section has a unique purpose.[4]

In the duodenum, food is mixed with pancreatic juices to be broken down even further for absorption.

Most absorption of nutrients takes place in the jejunum.

The ileum connects the small intestine to the large intestine. It also absorbs the last bit of nutrients available in the food.

5

Learn how your colon absorbs water. After the nutrients have been extracted from the food mass and absorbed by your body, the remaining waste is saturated with water. This water can be reabsorbed and reused by the body. The absorption of water happens in the large intestine (also known as the colon). Aside from keeping your body hydrated, this process also helps form a solid stool that your body can easily eliminate as waste.[5]

6

Think about how waste leaves the body. A buildup of waste in your body can be toxic. In order to prevent a buildup, your body has to shed the waste left behind after digestion. Waste is moved along the length of the long intestine until it reaches the anus. The anus allows waste to exit the body.[6]

The anus is very short. It is usually only about an inch long.

Method2

Learning the Processes of the Digestive System

1

Understand how food breaks down into smaller pieces. The first step of the digestive process takes place in the mouth. Your teeth are used to mechanically grind down foods into smaller, more manageable pieces. The smaller pieces provide more surface area for stomach acid to react to.[7]

2

Learn how enzymes are used to break down large molecules. The chemical breakdown of food molecules also starts in the mouth. Your saliva contains enzymes that begin breaking down food molecules while you chew. Once you swallow the food, it encounters more enzymes in the stomach and the duodenum. Some of the most common uses for enzymes are:[8]

Breaking proteins into amino acids

Breaking down complex carbohydrates into simpler ones

Breaking fats into simpler fats

3

Study the absorption of nutrients. Your digestive system absorbs the nutrients that the rest of your body needs. It passes these nutrients into the bloodstream, where they are carried to all of the cells of the body. Most nutrient absorption takes place in the jejunum, the second section of the small intestine.[9]

Additional nutrients are absorbed in the third chamber of the small intestine, the ileum. Even still, a very small amount of nutrients can be absorbed in the colon, also known as the large intestine.

4

Study the absorption of water. Once the nutrients have been taken from the food, your body has to prepare the leftover food mass for elimination. The first step is to solidify the mass. The colon is responsible for absorbing water from the food mass and forming it into solid feces. This also serves to keep your body hydrated.[10]

5

Understand how waste is eliminated. Once solid feces has been formed in the colon, it must exit the body. The waste moves the length of the colon until it reaches the anus. At the anus, your body expels the feces.[11]

Method3

Excelling in Anatomy and Physiology Classes

1

Read ahead of time. Anatomy and physiology classes cover a large volume of information in a short time. Lectures may go by quickly, and if you aren’t prepared, you can easily fall behind. Set aside time to read the upcoming chapters or sections before each class. Take notes on relevant information, and bring them to class with you.[12]

2

Make diagrams. Many of the structures in the body have names that are difficult to associate with the functions they serve. One way to help you keep track of different structures and systems is to create diagrams, or sketches, of each structure you study. These diagrams do not have to be drawn perfectly, but you should label all parts and make notes about the content of the picture.[13].

3

Join in class discussions. Some people can listen to an instructor give a lecture and retain nearly all of the information presented. Most people, however, struggle with this. Aside from taking class notes, you should join into any class discussions. The interaction will help solidify the information in your brain. Some ways you can contribute to a class discussion are:[14]

Ask questions if you do not understand something.

Answer sample questions given by your instructor.

Provide an argument to support your answer when appropriate.

4

Pay attention to lab classes. Anatomy and physiology labs will help you to relate the information you learn in class to real organisms. Choose a lab partner that is serious about doing well instead of picking a friend that you can goof off with. Split the work evenly, and make sure that each of you understand the lab in its entirety.[15]

Community Q&A

Are all foods digested in the stomach? I have heard that the pancreas also digests food is this true?

Community Answer

The pancreas provides enzymes to help break larger molecules into smaller molecules. The food does not enter the pancreas, instead the pancreas secretes juices into the small intestine to break down foods.

You can study the physiology of digestion in the human body by breaking down the digestive system into its different structures and parts. For example, remember that digestion begins in the mouth and the mouth contains different parts like the palate, uvula, tongue, and teeth. Once you learn each structure and its parts, focus on learning the process of each structure, or what it does. For example, in the stomach, enzymes break down food, and in the small intestines the bloodstream absorbs nutrients. It can be helpful to draw out diagrams of the structures of the body to help you study, especially if you have trouble remembering the names of different pieces of anatomy. To do this, make a rough sketch of each digestive system and label each part and what it does to move digestion along. To learn how to prepare yourself for lectures, read more from our Medical co-author.

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Article Info

This article was co-authored by Jennifer Boidy, RN. Jennifer Boidy is a Registered Nurse in Maryland. She received her Associate of Science in Nursing from Carroll Community College in 2012.